Drug interactions- summary-

Potentiates adverse effects of anticholinergics.

Concurrent use of TCAs leads to raised blood levels of both drugs

May antagonise  effects of levodopa , bromocriptine, and other dopamine antagonists

Avoid coadmin with drugs that cause electrolyle imbalance. 

Monitor phenytoin therapy due to inconsistent  effects of thioridazine on phenytoin levels.

Increased risk of QT prolongation  with class Ia, Class II  antiarrhythmics , astemizole,
cisapride, pimozide, droperidol, erythromycin IV, sparfloxacin, terfenadine, clarithromycin,
and other drugs that may prolong QT intervals

Potentiates CNS depression with opioids, .

Increased risk of arrhyhthmias with ephedrine-like drugs, eg phenylpropanolmine

Increased  risk of thioridazine levels with fluovoxamine, pinadol, propranol, ritonavir and
other CYP2D6 isoenzyme inhibitors eg. fluoxetine, paroxetine

Schizophrenia

Drowsiness,    sedation,    dry mouth,   nasal congestion,   

Blurring of vision,    tremor,    mydriasis,    constipation,

Urinary retention,    tachycardia,   postural  hypotension,

Sexual dysfunction,   pigmentary retinopathy (high doses  and prolonged therapy )

Contact dermatitis,   tardive dyskinesias,   neuroleptic malignant  syndrome,

Sudden deaths due to cardiac arrhthmias,  and arrest.

Hypersensitivity to phenothiazines,  comatose states pre-existing CNS depression

Special Precautions/Warnings-

Pregnancy,Lactation

Renal, hepatic impairment,epilepsy

Perform ECG screening,  and electrolyte measurements before therapy, and after each dose.

Increase at 6 monthly intervals.

Monitor for visual defects on long term therapy

May impair ability to perform skilled tasks.

Withdrawal of drug to be carried out over 1-2 weeks

Indication-

Schizophrenia

Dosage-

Adult-  initially 50-100mg tid daily and slowly titrated  upwards at no more than 100mg weekly.
Max  800mg daily in 2-4 divided doses

Child- 2-12 years - initially 0.5mg /kg daily in divided doses. Increase gradually until optimum
effect obtained.  Max. 3mg/kg daily.

Depression-  Adult- initially  25mg ititrated  to 20- 200mg daily

AVOID CONCURRENT USE WITH ERYTHROMYCIN

Use contraindicated. observe caution